The present invention generally relates to a folding article of the type in which its framework may be collapsed to provide a compact article for storage purposes. More particularly, the present invention relates to a collapsible chair and wheelchair.
It is well known that a collapsible chair is made of four pairs of cross legs located on four sides of the chair and pivotably connected intermediate their length, as disclosed, for example, by U.S. Pat. No. 3,136,272. In this patent, a pair of vertical back legs are located on the back side of the chair to support a flexible back rest. The vertical back legs and the cross legs are operatively associated with each other to support a flexible seat. A pair of arm rests are located on opposite sides of the collapsible chair. The arm rests are made of a flexible material so that the arm rests can readily be folded when the chair is collapsed in a scissors-like manner. Although the arm rests are preferably made of a rigid material, such rigid arm rests are difficult to manage when the chair is collapsed in two dimensions simultaneously.
It is, therefore, an object of the present invention to provide a collapsible chair and wheelchair which allow a pair of rigid arm rests to be moved from a horizontal operable position to a vertical storage position when the chair and wheelchair are collapsed in a scissors-like manner and also, returned to its horizontal operable position when the wheelchair is opened for use.
According to the present invention, there is provided a collapsible chair comprising a frame including a pair of front cross legs pivotally connected together intermediate their length, a pair of back cross legs pivotally connected together intermediate their length, two pairs of side cross legs pivotally connected together intermediate their length, a pair of vertical back legs located at opposite sides of the back cross legs, and means for interconnecting the front cross legs, the back cross legs, the side cross legs and the vertical back legs so as to move the collapsible chair between an expanded operable position and a collapsed position. The cross legs and the vertical back legs are collapsed in a scissors-like manner when the chair is folded up. A flexible seat is connected to the frame, and a back rest is connected between the vertical back legs. The seat and the back rest may be integrally formed from a single sheet. A pair of rigid arm rests are located on opposite sides of the collapsible chair. The arm rests may include a corresponding pair of elongated members having front and rear ends, and a corresponding pair of downwardly extending extensions having upper ends connected to the front ends of the elongated members and lower ends connected to the frame.
As a feature, means are provided to move the arm rests between a substantially horizontal operative position when the collapsible chair is held in its expanded operable position and a substantially vertical stored position when the collapsible chair is held in its collapsed position. The arm rests may be of a one-piece structure. In one embodiment, a pair of support rods are connected to and extend substantially parallel to the vertical back legs. A corresponding pair of sleeves are pivotably connected to the support rods and adapted to slidably receive the arm rests or the elongated members of the arm rests. This arrangement allows combined pivotably and slidable movement of the arm rests when the chair is moved between its expanded and collapsed positions and thus, enables the rigid arm rests to be smoothly moved between its horizontal operable and vertical stored positions. Alternatively, a pair of guide rods may be connected and extend substantially parallel to the vertical back legs, and a corresponding pair of slide blocks may be slidably mounted on the guide rods. The rear ends of the arm rests may be pivotably connected to the slide blocks. Still alternatively, a pair of support rods may be connected to and extend substantially parallel to the vertical back legs, and a corresponding pair of brackets may be pivotably connected to the support rods. A pair of rollers may be rotatably carried by the brackets and rollingly received within the arm rests or the elongated members of the arm rests.
Locking means may be provided to lock the arm rests against pivotal and sliding movement when the collapsible chair is held in its expanded operable and collapsed positions. In one embodiment, a pair of hooks are pivotably connected to the rear ends of the arm rests. A pair of upper locking pins are attached to the support rods, and a pair of lower locking pins are attached to the vertical back legs. The hooks are lockingly engageable with the upper locking pins to prevent inadvertent folding of the chair when the chair is held in its expanded operable position. Also, the hooks are lockingly engageable with the lower locking pins to prevent inadvertent unfolding of the chair when the chair is held in its collapsed position.
The collapsible chair may include four casters to provide a collapsible wheelchair. A front pair of casters and a rear pair of casters may be rotatably supported by the frame. The rear casters may include a pair of wheels, and a corresponding pair of pivotal levers operatively associated with the wheels to selectively stop the wheels. Preferably, the wheels have a corresponding pair of axles displaced rearwardly of the vertical back legs, and the levers may be positioned rearwardly of the axles. This arrangement facilitates operation of the levers.
Each of the front casters may include a pair of spaced wheels, and each of the rear casters may include a single wheel. This single wheel may be positioned between the two wheels of each of the front casters when the collapsible chair is folded to its collapsed position. This results in savings in space in which the wheelchair is stored.
The above and other objects, features and advantages of the present invention will be apparent from the following description of preferred embodiments when taken in conjunction with the accompanying drawings.